Throughout the day Thursday, emergency crews worked to reach the wreckage, which was strewn along the base of a sheer cliff in a rugged area of the mountains. Crews rappelled to reach the plane's remnants but found no survivors and quickly determined that the operation would focus on recovery instead of rescue.

Federal officials were still en route to the site Thursday afternoon. Once there, investigators would begin piecing together what took place just after sunset Wednesday on a flight that would leave Hardy, an experienced pilot, and the other passengers on the Rockwell twin-engine plane in such peril.

The children

Friends and acquaintances of the children's mother, Karen Perry of Apache Junction, expressed grief and sympathy for a selfless woman who has experienced a series of struggles in recent years. Morgan, the oldest, was diagnosed with epilepsy, undergoing multiple brain surgeries. Luke, the youngest, had autism.

"She just had some tragedies throughout her life, and some struggles," said Chandler resident Nicole Werner Hamming, who has known the mother for about 20 years through a mutual friend.

Mark Blomgren, principal at Peralta Trail Elementary in Apache Junction, said Logan and Morgan were in the school through the end of last year before they transferred schools.

Blomgren said the district's superintendent called him Thursday morning to share the news, and Blomgren immediately contacted teachers who had Logan and Morgan in their classes.

"They were just great kids," Blomgren said. "All the teachers were naturally shocked. They cared about them and wondered how their mom was doing and they were just hit pretty hard. Logan and Morgan were just special kids that the teachers really bonded with."

Karen and Shawn Perry entered divorce proceedings in Pinal County in 2009, according to public records.

The crew

Late Wednesday, LeeVon Motes, Hardy's cousin, described the story of how the men decided to take the flight.

Joseph Hardwick, the young mechanic, did not usually board a flight himself. But he did on Wednesday, likely just "tagging along" on a "nice trip on Thanksgiving Eve," said Pinal County Sheriff Paul Babeu, whose emergency crews mounted the search effort.

Coincidentally, the picture that sheriff's deputies used to identify the remains of Hardwick, youngest of seven children, was one taken at the Superstition Mountains while he was on a hiking trip.

"These people were really close and they were all family, even though they were not all related," Babeu said.

Hardy, 31, was the co-owner of Safford-based Ponderosa Aviation Inc., which owned the plane.

Hardy is survived by his wife, Joanna, and 3-year-old son Caden.

Acquaintances and those familiar with the Safford aviation community described the company as a "big family affair" run by a tight-knit family. On its website, the company touted decades of safe flying.

Allen Kenitzer of the Federal Aviation Administration said the plane that crashed was a Rockwell Aero Commander.

The company has contracts to provide firefighting services, said Ryan Owens, a pilot who owns a similar aviation-operating company based in Mesa. Owens said he and his business partner had researched Ponderosa Aviation because they were planning to purchase a business at the Safford Regional Airport.

"Mountain flying always has its difficulties, but these guys have operated with search, rescue and firefighting. To my knowledge, that's what they've done in the past. They would be very comfortable in that situation (of the crash)," Owens said.

The crash

The cause of the crash had not been identified by Thursday afternoon, pending a federal investigation, Babeu said.

The accident happened "just at the crest of this mountain, almost as if it would make it over," Babeu said.

Experienced pilots who have flown over the Superstition Mountains were perplexed by the crash. The area is not particularly difficult to fly over, they said. And even if both engines gave out, the aircraft would have been able to turn around and return to the airport by gliding, Owens said.

"What none of us know yet is why he (Hardy) would be that low in the area. The airplane performs so well, and he kept them maintained so well, that it's hard to understand why he would've let himself get that low in that area," said Howard Jenkins, a Graham County resident who has flown airplanes for 35 years.

Jenkins said Hardy was a "very dedicated man, hard worker," and a "very experienced pilot."

The plane departed from Falcon Field at 6:15 p.m. Wednesday. An explosion at the southwest portion of the Superstition Mountains was reported at 6:31 p.m., Babeu said. The crash site was near the peaks' Flat Iron area, he said.

Sheriff's deputies camped at the crash site overnight because the area, surrounded by rugged terrain, was too treacherous for deputies to search for bodies overnight, Babeu said.

Babeu estimated the plane was traveling at about 200 mph at the point of collision. The speed, combined with reports of a fiery explosion and the amount of debris on the scene, led officials to believe all of the passengers were dead, Babeu said.

Investigators from the National Transportation Safety Board and the FAA were expected later Thursday, Babeu said. NTSB investigators issue a preliminary report within several days of an accident; a final report could take several months.

Pinal County's first responders knew they were looking at a tragedy as soon as they arrived on the scene Wednesday, Babeu said.

"No one could survive that crash," Babeu said. "All of these families are just obviously heartbroken, traumatized over the loss of their loved ones so suddenly and on Thanksgiving."

How to help

Members of the public looking to help with funeral expenses can donate to the Perry family through a funeral fund at the Gold Canyon Bank, at 6641 S. Kings Ranch Road, No. 2, Gold Canyon, AZ 85118.